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To change or adjust the range of measurement, first perform the zero adjustment and then that of the
measurement scale using the external adjusting screw (do not use in nuclear power plants) on the LCD
indicator (do not use in nuclear power plants) or with the mobile communicator (if the zero adjustment
is done after the adjustment of the measurement scale, the point 100% cannot be adjusted correctly).
The zero corresponds to the output signal 4mA (LRV - 0%) and the measurement scale at 20mA
(URV-100%)
For nuclear power plants, the FXW mobile communicator must be used for all the adjustments.
6.1 Adjustments with the FXW mobile communicator (HHC)
For nuclear power plants, the zero adjustment may be performed only with the aid
of a mobile communicator and only when the FCX-IIA pressure transmitter is not in
service.
The measuring range of the transmitter is easily adjustable by using the keys on the keyboard of
the FXW without any pressure generation.
This applies if the calibration of the transmitter has not been modified since its manufacture or
since a last calibration carried out by competent staff with precise generation of pressure.
For more details on the FXW, refer to its specific user manual.
Note:
* The mobile communicator must be in the OFF position during the connection. It may not be
connected to the test terminal CK
+
and CK
-
of the transmitter terminal block.
* The mobile communicator is not polarised (the wires of the FXW can be connected equally to
the
+
or
-
terminals of the transmitter or the wires of the 4-20mA loop).
4.1.1 Connection of the FXW communicator (HHC)
The mobile communicator can be connected at any point of the measurement loop. A resistance
of minimum load of 250Ω is necessary for
perfect communication.
Refer to the diagram below for the connection
of the FXW.
ADJUSTMENTS AND SETTINGS
6
After performing the settings, maintain the electrical supply for at least
10 seconds.
If the sender is installed in a hazardous zone (explosion-proof), the FXW
mobile communicator may only be connected to junction boxes located
outside dangerous zone.
DANGER
Never connect an FXW mobile communicator directly to the terminal block of
the transmitter in an explosion-proof atmosphere.
DANGER
INDICATION
Important
CK
–
CK
+
+
–
Field device
To junction
terminal or
To HHC
instrument
room
Instrument room
Junction terminal
Zener barrier
Terminal block
DC power supply
16.1 to 45V DC
Load resistor
250 or more
Note)
Note) See
“Power voltage and load resistance”.
HHC = Hand Held Communicator
